<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title>CSS选择器</title>
		<style>
			/*标记选择器*/
			div{
				color:red;
			}
			p{
				color:greenyellow;
			}
			/*id选择器*/
			#sy1{
				 font-size: 20px;
			}
			#sy2{
				color: #982585;
			}
			/*class选择器*/
			.nuc{
				 font-size: 45px;
				 color: blue;
			}
		</style>
	</head>
	<body>
		<div class="nuc">实验</div>
		<div id="sy1">1实验1</div>
		<div id="sy2">2实验2</div>
		<div id="sy3">3实验3</div>
		<p class="nuc">这是个段落</p>
	</body>
</html>
